Conveyor dishwasher

ABSTRACT

A conveyor dishwasher ( 1 ) having at least one wash zone ( 10, 11.1, 11.2, 12 ) and at least one final rinse zone ( 13 ) and also having a conveyor apparatus ( 2 ) for conveying washware ( 100, 101, 102, 103 ) through the at least one wash zone ( 10, 11.1, 11.2, 12 ) and the at least one final rinse zone ( 13 ). In order to make the entire washing and rinsing process more efficient, provision is made for the conveyor apparatus ( 2 ) to have a first conveyor belt ( 50 ) for trays or tray-like washware ( 100 ) and a second conveyor belt ( 51 ), which runs parallel to the first conveyor belt ( 50 ), for other washware ( 101, 102, 103 ), with the first conveyor belt ( 50 ) having a width which is reduced in comparison to the second conveyor belt ( 51 ) in such a way that a tray or a tray-like item ( 100 ) of washware can be held by the first conveyor belt ( 50 ) only when it is in a state in which it is placed on edge and is oriented parallel to the conveying direction (T).

The invention relates to a conveyor dishwasher and, in particular, to aconveyor dishwasher having at least one wash zone and at least one finalrinse zone and also having a conveyor apparatus for conveying washwarethrough the at least one wash zone and the at least one final rinsezone.

The conveyor dishwasher according to the invention is, in particular, acommercial conveyor dishwasher and can be in the form of a flight-typedishwasher (flight-type warewasher) or a rack-conveyor dishwasher(rack-conveyor warewasher).

Conveyor dishwashers (conveyor warewashers) are used in the commercialsector. In contrast to domestic dishwashers, in which the washware to becleaned remains stationary in the machine during cleaning, in conveyordishwashers the washware is conveyed through various treatment zones ofthe machine.

In the case of conveyor dishwashers, the washware, for example trays,tableware, pots, glasses, cutlery and other articles which are to becleaned, is conveyed through a plurality of treatment zones, for exampleprewash zone(s), main wash zone(s), postwash or prerinse zone(s), finalrinse zone(s) and drying zone(s). A conveyor apparatus which generallyhas compartments for holding washware is used to convey washware in aconveying direction through the conveyor dishwasher. In the case of aflight-type dishwasher, the compartments can be formed by supportingfingers on a conveyor belt of the conveyor apparatus. In the case ofrack-conveyor dishwashers, dish racks in which compartments can beformed in order to hold the washware to be treated serve as the conveyorapparatus. It is feasible here for the dish racks to be conveyed throughthe rack-conveyor dishwasher by a conveying device.

The washware to be cleaned is usually presorted before being placed onthe conveyor belt. For example, U.S. Pat. No. 6,530,996 B2 discloses arack-conveyor dishwasher in which the washware to be treated is fed tothe respective treatment zones in a state in which it is presorted indish racks.

With regard to tray or tray-like articles, the presorting process isusually performed by the set of tableware and cutlery being removed froma tray to be cleaned and the tray then being stacked in front of theconveyor apparatus or in the feed region (dirty side) of the conveyordishwasher. The trays from this stack of trays are from time to timeplaced, in manner sorted by type, in the conveyor belt of the dishwasherand cleaned. This procedure of sorting by type has the advantage thattrays cannot cast spray shadows over smaller items of washware whichhave been stacked behind the trays. Furthermore, this procedure greatlysimplifies the sequence of work for stacking and destacking and makes itmore efficient in comparison to mixing the washware with the trays to becleaned.

However, while the trays from this stack of trays are placed, in amanner sorted by type, in the conveyor belt of the dishwasher andcleaned, it is not possible to clean other washware, for example plates,bowls or other tableware, since the trays which are to be placed in theconveyor belt usually have to be placed in the conveyor belt transverseto the conveying direction and therefore take up all the availablesurface area of the conveyor belt. Therefore, a relative large amount oftime is required to clean trays in comparison to other types ofwashware.

Furthermore, the operating personnel of the conveyor dishwasher at themachine inlet have to include each tray twice in their sequence of work:the first time when removing the items of cutlery and tableware from thetray to be cleaned and the second time when actually placing the tray inthe conveyor belt of the conveyor dishwasher.

On the basis of this problem, the object of the present invention is todevelop a conveyor dishwasher of the type cited in the introductory partin such a way that this enables the entire washing and rinsing processto be made more efficient, as a result of which, in particular, theworking time of the dishwashing personnel can be reduced and theconsumption of resources by the dishwasher can be reduced.

According to the invention, this object can be achieved by the subjectmatter claimed below.

In this regard, a typical tray or tray-like item of washware has alengthwise dimension and a widthwise dimension, where the widthwisedimension is smaller than the lengthwise dimension. The end edges of thetray or tray-like washware item define the lengthwise dimension and thesides edges of the tray or tray-like washware item define the widthwisedimension.

In accordance with the subject matter, the invention proposes that theconveyor apparatus of the conveyor dishwasher has a first conveyor beltfor trays or tray-like washware, and a second conveyor belt, which runsparallel to the first conveyor belt, for other washware, with the firstconveyor belt having a width which is reduced in comparison to thesecond conveyor belt in such a way that a tray or a tray-like item ofwashware can be held by the first conveyor belt only when it is in astate in which it is placed on edge and is oriented parallel to theconveying direction.

The tray or tray-like washware may typically be placed on either an endedge or a side edge on the first conveyor belt. The tray or tray-likewashware item is considered oriented parallel to the conveying directionif either the lengthwise dimension or the widthwise dimension of thetray or tray-like washware item runs substantially paralallel to theconveying direction.

The term “width of the conveyor belt” used here is to be understood tomean the horizontal extent of the conveyor belt transverse, that is tosay perpendicular, to the conveying direction.

Since a separate conveyor belt (first conveyor belt) is provided in theconveyor dishwasher according to the invention for trays or tray-likearticles, it being possible for trays or tray-like articles to be in astate in which they are placed on edge and are oriented parallel to theconveying direction in the conveyor belt, it is possible for the traysor tray-like articles to be cleaned with other washware at the sametime, without the risk of the trays or tray-like articles casting aspray shadow on the washware which is to be cleaned at the same time asthe trays or tray-like articles during cleaning.

Furthermore, the orientation of the trays or tray-like articles parallelto the direction in which the first and second conveyor belts runresults in minimal utilization of the surface area of the total beltsurface area. This minimal utilization of surface area means that thesecond conveyor belt, which is provided for the other washware, cancontinue to be used virtually without restriction. Both racks of glassesand GN containers can be placed on the second conveyor belt next to atray which is disposed on the first conveyor belt.

Therefore, the arrangement of two conveyor belts reduces the length ofthe overall washing and rinsing process in a commercial scullery andtherefore reduces the working time of the dishwashing personnel andalso, secondly, reduces the consumption of resources by the conveyordishwasher.

In a preferred embodiment of the solution according to the invention,provision is made for the conveying speed of the first conveyor belt tobe increased relative to the conveying speed of the second conveyorbelt. This increase in the conveying speed enables each tray to beplaced in position, without delay, at the time at which all the items ofcutlery and tableware are removed from the tray. Accordingly, it ispossible for the trays to not be deposited in a stack after the items oftableware and cutlery possibly present on the tray are removed fromthem, but rather for the trays to be placed directly into the firstconveyor belt. Therefore, a second working step involving the respectivetray is dispensed with in this embodiment. Automatic destacking of traysat the machine outlet is likewise preferred for this machineconfiguration since, under certain circumstances, the operatingpersonnel at the machine outlet may be unable to cope with destackingthe conveyor dishwasher on account of the cleaning processes running inparallel on the two conveyor belts.

The concept of providing a separate conveyor belt for specific types ofwashware can be extended as desired and various combinations ofindividual conveyor belts are possible. Therefore, in a preferredembodiment of the solution according to the invention, provision is alsomade for at least one further conveyor belt, which runs parallel to thefirst and second conveyor belts, to be used, with this further conveyorbelt preferably being provided for items of cutlery. In this case, it ispreferred when the further conveyor belt which is provided for items ofcutlery runs directly next to the first conveyor belt and between thefirst and second conveyor belts. In this embodiment, it is no longernecessary for the operator of the conveyor dishwasher to manually removethe set of cutlery from the respective tray at the machine inlet. Sincethe tray is placed on edge in order to be fed and placed on the firstconveyor belt, the set of cutlery falls automatically—driven by theforce of gravity—from the upended tray into the cutlery lane (furtherconveyor belt) and likewise into a provided container after washing anddrying. Therefore, the handling actions for the cutlery are completelydispensed with.

Furthermore, special lanes for individual types of washware, for exampleplates and/or bowls, can be provided since automatic destacking systemsfor all these types of washware are already known from semi- and fullyautomatic technology. On account of the degree of automation which isincreased by virtue of these special lanes in conjunction with automateddestacking, working time can be saved both at the clean end and at thedirty end of the conveyor dishwasher. The dishwashing process thereforeruns more efficiently and its overall length is reduced, so that, inaddition to working time, resources can be saved.

The invention will be described below by way of example on the basis ofvarious embodiments and with reference to the drawings. Parts which arethe same or have the same functions are provided with the same referencenumerals here.

In the drawings:

FIG. 1 shows a schematic longitudinal view of a conveyor dishwasher inwhich a conveyor apparatus according to the invention can be used totreat (clean and dry) a plurality of types of washware, which arearranged next to one another, at the same time;

FIG. 2 a shows a plan view of a sub-region of a first exemplaryembodiment of a conveyor apparatus which can be used in a conveyordishwasher according to FIG. 1;

FIG. 2 b shows a cross-sectional view of the conveyor apparatusaccording to FIG. 2 a;

FIG. 3 a shows a plan view of a sub-region of a second exemplaryembodiment of a conveyor apparatus which can be used in a conveyordishwasher according to FIG. 1;

FIG. 3 b shows a cross-sectional view of the conveyor apparatusaccording to FIG. 3 a;

FIG. 4 a shows a plan view of a sub-region of a third exemplaryembodiment of a conveyor apparatus which can be used in a conveyordishwasher according to FIG. 1; and

FIG. 4 b shows a cross-sectional view of the conveyor apparatusaccording to FIG. 4 a.

FIG. 1 shows a schematic longitudinal view of an exemplary embodiment ofa conveyor dishwasher 1 in which a conveyor apparatus 2 is used forconveying washware (not illustrated in FIG. 1) through the conveyordishwasher 1 in a conveying direction T. As will be described later withreference to the illustrations in FIGS. 2 to 4, the conveyor apparatus 2is designed, according to the invention, to treat (clean and dry) aplurality of types of washware, which are arranged next to one another,at the same time, in order to thus make the entire washing and rinsingprocess more efficient, as a result of which, in particular, the workingtime of the dishwashing personnel can be reduced and the consumption ofresources by the dishwasher can be reduced.

As can be seen in the illustration in FIG. 1, the conveyor dishwasher 1according to the exemplary embodiment has at least one wash zone (asillustrated in FIG. 1 for example), a prewash zone 10 and two main washzones 11.1, 11.2 which are arranged downstream of the prewash zone 10 asseen in the conveying direction T.

As seen in the conveying direction T, a postwash zone 12 is arrangeddownstream of the at least one wash zone 10, 11.1, 11.2, and at leastone final rinse zone, for example only a single final rinse zone 13 asillustrated, is arranged downstream of the postwash zone 12. In theconveyor dishwasher 1 illustrated in FIG. 1, the final rinse zone 13 isfollowed in the conveying direction T of the washware by a drying zone14.

The respective zones 10, 11.1, 11.2, 12, 13, 14 of the conveyordishwasher 1 can be separated from one another by means of separatingcurtains 5. In the embodiment illustrated in FIG. 1, the inlet tunnel 3of the conveyor dishwasher 1 itself is also separated from the inlet 4by means of a separating curtain 5. The provision of the separatingcurtains 5 prevents wash liquid and final rinse liquid spraying betweenzones and prevents vapours escaping from the conveyor dishwasher 1.

The treatment zones 10, 11.1, 11.2, 12, 13 of the conveyor dishwasher 1have associated spray nozzles 30 a, 30 b, 31.1 a, 31.1 b, 31.2 a, 31.2b, 32 a, 32 b, 33 a, 33 b, 33 c. These spray nozzles 30 a, 30 b, 31.1 a,31.1 b, 31.2 a, 31.2 b, 32 a, 32 b, 33 a, 33 b, 33 c serve to sprayliquid onto the washware which is to be treated as the washware isconveyed through the respective treatment zones 10, 11.1, 11.2, 12, 13by the conveyor apparatus 2. The individual spray systems of thetreatment zones 10, 11.1, 11.2, 12, 13 ensure that the washware which isto be treated is hosed down both from the top and from the bottom.

However, in the conveyor dishwasher 1 schematically illustrated in FIG.1, the final rinse zone 13 not only has downwardly directed upper spraynozzles 33 a and upwardly directed lower spray nozzles 33 b, but alsotransversely directed lateral final rinse nozzles 33 c on either side ofthe conveyor apparatus 2. The use of lateral final rinse nozzles 33 cpermits areas of the washware (areas of the tableware) to be sprayedwith final rinse liquid in a targeted manner in shadow zones too. Theuse of lateral final rinse nozzles 33 c in the final rinse zone 13 has asignificant advantage in terms of the final rinse result (effectiverinsing-off of detergent residues from surfaces of the tableware inshadow zones too) compared to systems in which only upper and lowerfinal rinse nozzles 33 a, 33 b and no transversely directed lateralfinal rinse nozzles 33 c are provided in the final rinse zone 13,specifically when the conveying system is fully loaded, for example withplate-to-plate loading of the dish rack.

The postwash or prerinse zone 12, main wash zones 11.1, 11.2 and prewashzone 10 also have associated tanks (postwash tank 22, main wash tank21.1, 21.2, prewash tank 20) for accommodating sprayed liquid and/or forproviding liquid for the spray nozzles 30 a, 30 b, 31.1 a, 31.1 b, 31.2a, 31.2 b, 32 a, 32 b of the relevant treatment zones 10, 11.1, 11.2,12.

As already indicated, final rinse liquid, which comprises fresh waterwith rinse aid which is added in a metered fashion, is sprayed onto thewashware (not illustrated) by means of final rinse nozzles 33 a, 33 b,33 c which are arranged above and below the conveyor apparatus 2 and onthe side in the conveyor dishwasher 1 illustrated in FIG. 1. A portionof the sprayed final rinse liquid is conveyed from treatment zone totreatment zone via a cascade system in the opposite direction to theconveying direction T of the washware. The remaining portion of thefinal rinse liquid sprayed in the final rinse zone 13 is conducteddirectly to the prewash tank 20 which is associated with the prewashzone 10 via a valve V1 and a bypass line 6.

In the cascade system, the final rinse liquid sprayed by the final rinsenozzles 33 a, 33 b, 33 c flows from the final rinse zone 13 into thepostwash tank 22, which is associated with the postwash zone 12, due tothe force of gravity. The final rinse liquid sprayed in the final rinsezone 13 and collected by the postwash tank 22 is then delivered to thespray nozzles of the postwash zone 12 (upper and lower postwash nozzles32 a, 32 b) with the aid of a postwash pump 36.

Wash liquid is rinsed off from the washware in the postwash zone 12. Theliquid (postwash liquid) produced in the process flows into the firstmain wash tank 21.1, which is associated with the first main wash zone11.1, due to the force of gravity. A discharge element 7, for example adischarge base or a baffle plate, which conducts the postwash liquidsprayed by the postwash nozzles 32 a, 32 b into the main wash tank 21.1is preferably provided for this purpose. According to another embodiment(not illustrated) of the conveyor dishwasher 1, the outlet element 7 canbe dispensed with if the main wash tank 21.1 extends as far as beneaththe postwash nozzles 32 a, 32 b of the postwash zone 12.

The liquid accommodated by the main wash tank 21.1 of the first mainwash zone 11.1 is usually provided with a detergent and sprayed onto thewashware by means of the spray nozzles of the first main wash zone 11.1(upper and lower main wash nozzles 31.1 a, 31.1 b) with the aid of afirst main wash pump 35.1. The wash liquid which is sprayed by the mainwash nozzles 31.1 a, 31.1 b then flows back into the main wash tank 21.1due to the force of gravity.

The main wash tank 21.1 is fluidically connected to the main wash tank21.2, which is associated with the second main wash zone 11.2, via anoverflow line 9.1. The wash liquid which is sprayed in the first mainwash zone 11.1 enters the main wash tank 21.2 of the second main washzone 11.2 via this overflow line 9.1 when there is a sufficient quantityof wash liquid in the main wash tank 21.1 of the first main wash zone11.1.

The liquid accommodated by the main wash tank 21.1 of the second mainwash zone 11.2 is sprayed onto the washware by means of the spraynozzles of the second main wash zone 11.2 (upper and lower main washnozzles 31.2 a, 31.2 b) with the aid of a second main wash pump 35.2.The wash liquid which is sprayed by the main wash nozzles 31.2 a, 31.2 bthen flows back into the main wash tank 21.2 of the second main washzone 11.2 due to the force of gravity.

The main wash tank 21.2 of the second main wash zone 11.2 is fluidicallyconnected to the prewash tank 20 which is associated with the prewashzone 10 via an overflow line 9.2. The wash liquid which is sprayed inthe second main wash zone 11.2 enters the prewash tank 20 via thisoverflow line 9.2 when there is a sufficient quantity of wash liquid inthe main wash tank 21.2 of the second main wash zone 11.2.

The liquid accommodated in the prewash tank 20 of the prewash zone 10 isthen sprayed onto the washware by means of the spray nozzles of theprewash zone 10 (upper and lower prewash nozzles 30 a, 30 b) with theaid of a prewash pump 34, in order to remove coarse particles of dirtfrom the washware. The wash liquid which is sprayed by the prewashnozzles 30 a, 30 b then flows back into the prewash tank 20 due to theforce of gravity.

The prewash tank 20 is provided with an overflow line 8 which is used tofeed the excess quantity of liquid to a waste water system if a specificliquid level in the prewash tank 20 is exceeded.

As already indicated, the liquid which is sprayed in the main wash zones11.1, 11.2 and in the prewash zone 10 preferably contains detergentwhich is added in a metered fashion with the aid of a detergent meteringapparatus (not shown in the drawings), for example, to the liquid whichis accommodated in the main wash tank 21.1 of the first main wash zone11.1.

As already mentioned, the final rinse zone 13 is followed by the dryingzone 14 in the conveying direction T. In the drying zone 14, thewashware is dried using dry and heated air in order to blow off and/ordry up the moisture on the washware. In order to keep the moisturecontent of the air in a range which is expedient for drying, it isfeasible, for example, to supply external room air to the drying zone 14via an opening, for example through the outlet opening for the washware.

The warm and moisture-laden air in the drying zone 14 is then drawn-offfrom the drying zone 14 via a further opening, for example with the aidof a fan 15. It is advantageous here if the exhaust-air stream from thedrying zone 14 passes a heat recovery device 16 in which, for example, acondenser can be provided. The heat recovery device 16 serves to recoverat least some of the thermal energy contained in the exhaust air. Thisrecovered thermal energy can be used, for example, to heat the liquidwhich is to be sprayed in the final rinse zone 13.

If, before initial starting of the conveyor dishwasher 1, the tanks(prewash tank 20, main wash tank 21.1, 21.2, postwash tank 22) which areassociated with the treatment zones 10, 11.1, 11.2, 12 are empty orinsufficiently filled, the tanks first have to be filled via a freshwater line 18 and/or by spraying final rinse liquid in the final rinsezone 13. The fresh water line 18 can be connected to a fresh watersupply system via an actuable valve V3. The quantity of wash liquidavailable in the main wash zones 11.1, 11.2 and in the prewash zone 10can in each case be monitored and signalled to a control device 40 withthe aid of a level sensor which is provided in the main wash tank 21.1,21.2 of the first and/or second main wash zone 11.1, 11.2 and with theaid of a level sensor which is provided in the prewash tank 20.

The final rinse zone 13 can—as illustrated in FIG. 1—have an associatedfresh water container 23 for temporarily storing at least a portion ofthe fresh water which is provided for final rinsing purposes. The freshwater container 23 is firstly provided with a fresh water connectionwhich can be connected to a fresh water supply system via an actuablefresh water feed valve V2. Secondly, the fresh water container 23 isconnected to the intake end of a final rinse pump 37.

The delivery end of the final rinse pump 37 is connected to the upstreamend region 47 of a main line system 44 by means of which fresh water isconveyed from the fresh water container 23 to the final rinse nozzles 33a, 33 b, 33 c when the final rinse pump 37 is operated. Specifically,the main line system 44 connects the delivery end of the final rinsepump 37 to a water heater 17 (boiler). In this case, the main linesystem 44 is designed in such a way that the liquid which is suppliedfrom the final rinse pump 37 to the final rinse nozzles 33 a, 33 b, 33 cfirst passes the heat recovery device 16 before reaching the waterheater 17. In this way, it is possible to use at least some of thethermal energy of the exhaust air which is discharged to the drying zone14 to heat up the liquid which is supplied to the spray nozzles 33 a, 33b, 33 c via the main line system 44.

Various embodiments of conveyor apparatuses 2 for conveying washwarethrough the conveyor dishwasher 1 which is schematically illustrated inFIG. 1 will be described below with reference to the illustrations inFIGS. 2 a to 4 b.

Specifically, FIGS. 2 a and 2 b schematically show a region of a firstexemplary embodiment of a conveyor apparatus 2 which is suitable for usein a conveyor dishwasher 1 according to the illustration in FIG. 1. Inthis case, FIG. 2 a shows a plan view of the machine outlet-end regionof the conveyor apparatus 2, while FIG. 2 b illustrates thecorresponding cross-sectional view.

Accordingly, the conveyor apparatus 2 which is illustrated in FIGS. 2 aand 2 b has a first conveyor belt 50 for trays or tray-like washware 100and also a second conveyor belt 51, which runs parallel to the firstconveyor belt 50, for other washware, in particular plates 101, bowls102 and/or cutlery 103. The first conveyor belt 50 is relatively narrowin comparison with the second conveyor belt 51, and therefore a tray ortray-like item 100 of washware can be held by the first conveyor belt 50only in a state in which it is placed on edge and is oriented parallelto the conveying direction T. The orientation of the washware 100 whichis to be held by the first conveyor belt 50 parallel to the direction inwhich the first conveyor belt 50 runs results in minimal utilization ofthe surface area of the total belt surface area. In other words, thefirst conveyor belt 50 has a width which is reduced in such a way thatonly a minimal surface area of the total belt surface area is occupiedby the first conveyor belt 50, this specifically permitting trays ortray-like washware 100 to be placed in position when this washware 100is in a state in which it is placed on edge and is oriented parallel tothe conveying direction T.

This means that it is possible for the second conveyor belt 51, asbefore, to have a sufficient width in order to continue to be able to beused almost without restriction for conveying other washware, inparticular plates 101, bowls 102 and/or cutlery 103, through theindividual treatment zones of the conveyor dishwasher 1. Therefore, forexample, racks of glasses or GN containers can, as before, also beplaced on the second conveyor belt 51 next to the tray or tray-like item100 of washware which is held on the first conveyor belt 50.

In the embodiment which is illustrated in FIGS. 2 a and 2 b, a tray 100and two plates 101 are arranged next to one another merely as anexample, with the tray 100 being disposed on the first conveyor belt 50of the conveyor apparatus 2 and the plates 101 being disposed on thesecond conveyor belt 51 of the conveyor apparatus 2. In this embodiment,the plates 101 are retained on the second conveyor belt 51 with the aidof compartments, with these compartments being formed by supportingfingers 63 which are provided on the second conveyor belt 51.

As already indicated, the second conveyor belt 51 has—despite theprovision of a first conveyor belt 50 which runs parallel to the secondconveyor belt 51—a sufficient width to also be able to accommodateconventional racks of glasses etc. This is achieved without the conveyordishwasher 1 having to have a conveyor apparatus 2 which is wideroverall.

The solution according to the invention therefore allows both trays ortray-like washware 100 and other washware, in particular plates 101,bowls 102 and/or cutlery 103, to be cleaned at the same time. Therefore,cleaning processes which proceed in parallel can be implemented on bothconveyor belts 50, 51, this ultimately reducing the total length of thewashing and rinsing process in a commercial scullery. This in turnreduces the working time of the dishwashing personnel and leads to areduction in the consumption of resources by the conveyor dishwasher 1.

As can be seen in the illustration in FIG. 2 b in particular, the firstconveyor belt 50 is designed to hold trays or tray-like washware 100 inthe exemplary embodiment of the conveyor apparatus 2, with this washwarebeing supported on the first conveyor belt surface by means of a borderor edge region 100′. In order to securely retain the tray-like washware100 which is held on the first conveyor belt 50 and is placed on edge,it is advantageous, in particular, if a guide which is associated withthe first conveyor belt 50 is provided. This guide preferably serves notonly to retain the washware 100 on the first conveyor belt 50, but alsoto guide the washware 100 which is held on the first conveyor belt 50 asit is conveyed through the respective treatment zones of the conveyordishwasher 1.

In the embodiment of the conveyor apparatus 2 which is illustrated inFIGS. 2 a and 2 b, a guide of this kind is implemented in the form of alower guide groove at one end and in the form of an upper guide rail atthe other end. The illustration in FIG. 2 b shows, in particular, that aguide groove 60, which is formed in the first conveyor belt 50 and runsin the longitudinal direction of the first conveyor belt 50, is designedto guide and retain the tray-like item 100 of washware which is held onthe first conveyor belt 50. This guide groove 60 serves to hold a borderor edge region 100′ of a tray or tray-like item 100 of washware which isplaced on the first conveyor belt 50.

In addition to the (lower) guide groove, 60, an upper guide element 61,which is situated opposite the first conveyor belt 50 and is implementedas a guide rail in this case, is used in the embodiment which isillustrated in FIGS. 2 a and 2 b. As indicated in FIG. 2 b, this guideelement 61 is designed to hold a region 100″ of a tray or tray-like item100 of washware which is placed on the first conveyor belt 50 and toguide the washware 100 as it is conveyed through the individualtreatment zones of the conveyor dishwasher 1. It is clear that thewashware 100 which is placed on edge on the first conveyor belt issecurely retained on the first conveyor belt 50 on account of theprovision of the lower guide groove 60 and of the upper guide element61.

As can be seen in the illustration in FIG. 2 b, the upper guide element61 is preferably designed to hold a region 100″ of the tray or tray-likeitem 100 of washware which is placed on the first conveyor belt 50,which region 100″ is situated opposite the border or edge region 100′ bymeans of which the tray or tray-like item 100 of washware is supportedon the first conveyor belt 50.

In order to be able to hold trays or tray-like washware with differentdimensions on the first conveyor belt 50, it is advantageous if theupper guide element 61 is adjustable in the vertical direction. In thisway, the upper guide element 61, in a manner which is simple toimplement, can be matched to the height of a tray or tray-like item 100of washware which is to be held by the first conveyor belt 50 and isplaced on edge. Accordingly, the first conveyor belt 50 is suitablefirstly for holding trays 100 which are supported on the first conveyorbelt 50 by means of their longitudinal side edge, and secondly forholding trays 100 which are supported on the first conveyor belt 50 bymeans of their transverse side edge. Therefore, the first conveyor belt50 can be used flexibly for various applications.

The illustration in FIG. 2 b, in particular, shows that a belt guide 62which is associated with the first conveyor belt 5 is provided in theexemplary embodiment of the conveyor apparatus 2 which is schematicallyshown in said illustration. A belt guide 62 of this kind isadvantageous, in particular, when—as in the embodiment which isillustrated in FIGS. 2 a and 2 b—the first conveyor belt 50 is in theform of an endless drive belt. The provision of a belt guide 62 of thiskind ensures, in a simple to implement yet effective manner, that thefirst conveyor belt 50 always runs parallel to the second conveyor belt51. Furthermore, it has proven advantageous if the first conveyor belt50 is in the form of a flat belt, a V-belt, a toothed belt or a roundbelt, in order to provide additional guidance of the first conveyor belt50.

As indicated in FIG. 2 b, the belt guide 62 which is associated with thefirst conveyor belt 50 can be fixed, for example, to belt rod shafts 55of the second conveyor belt 51, as a result of which the conveyorapparatus 2 is provided with a compact design. However, it goes withoutsaying that other embodiments for fixing the belt guide 62 are feasible.

As already cited, a guide groove 60, which is formed in the firstconveyor belt 50 and runs in the longitudinal direction of the firstconveyor belt 50, is provided in the embodiment which is illustrated inFIGS. 2 a and 2 b, it being possible for a border or edge region 100′ ofa tray or tray-like item 100 of washware which is placed on the firstconveyor belt 50 to be held in the guide groove in order to guide thewashware 100 which is placed on edge on the first conveyor belt 50 as itis conveyed through the respective treatment zones of the conveyordishwasher 1. However, instead of a guide groove 60 of this kind, it isalso feasible for the belt guide 62 to be used to not only guide thefirst conveyor belt 50, but also the washware 100, which is placed onthe first conveyor belt 50, as it is conveyed through the respectivetreatment zones of the conveyor dishwasher 1. If—as illustrated in FIG.2 b—the belt guide 62 is in the form of a vertically oriented guideface, this vertically oriented guide face can, at the same time, serveas a stop face for a border or edge region 100′ of a tray or tray-likeitem 100 of washware which is held on the first conveyor belt 50 and isplaced on edge. Although not illustrated in the drawings, it istherefore feasible for the border or edge region 100′ of the tray ortray-like item 100 of washware which is held on the first conveyor belt50 and is placed on edge to be supported on the vertically orientedguide face of the belt guide 62, this enabling the washware 100 which isheld on the first conveyor belt 50 to be guided through the respectivetreatment zones of the conveyor dishwasher 1.

In one possible implementation, the upper guide element 61 is in theform of a guide rail. This guide rail preferably runs in such a way thata tray or tray-like item 100 of washware, which is held on the firstconveyor belt 50, is transferred from its state in which it is placed onedge to its horizontally oriented normal state and then destacked at theoutlet of the conveyor dishwasher 1, that is to say downstream of the atleast one final rinse zone 13 as seen in the conveying direction T. Inthis embodiment, the tray or tray-like washware 100 which was originallyheld on the first conveyor belt 50 is therefore automatically destackedat the machine outlet, this enabling a further reduction in operatingpersonnel at the machine outlet.

It is preferred, in principle, if the first conveyor belt 50, which isprovided for conveying trays or tray-like washware 100, has a higherconveying speed in comparison to the second conveyor belt 51 which isprovided for other washware. The increase in the conveying speed enablesthe trays or the tray-like washware 100 to be placed in position,without delay, at the time at which all the items of cutlery andtableware are removed from the tray. Therefore, the trays 100 are notdeposited in a stack after the items of tableware and cutlery areremoved, but rather are placed directly into the first conveyor belt 50.Therefore, a second working step with the respective tray 100 isdispensed with in this embodiment.

In a preferred implementation of the last-mentioned embodiment,provision is made for a common drive apparatus to be provided for thefirst and second conveyor belts 50, 51, the first and second conveyorbelts 50, 51 being jointly driven by means of the common driveapparatus. The provision of a common drive apparatus simplifies theoverall design of the conveyor dishwasher.

In order to be able to implement different conveying speeds in a commondrive apparatus for the first and second conveyor belts 50, 51, it isfeasible for the first conveyor belt 50 to be connected to the commondrive apparatus by means of a first drive shaft which is associated withthe first conveyor belt 50 and a first gear mechanism apparatus which isassociated with the first conveyor belt 50, while the second conveyorbelt 51 is connected to the common drive apparatus by means of a seconddrive shaft which is associated with the second conveyor belt 51 and asecond gear mechanism apparatus which is associated with the secondconveyor belt 51. The respective transmission ratio of the first and thesecond gear mechanism apparatus is preferably selected in such a waythat the conveying speed at which an item 100 of washware which is heldby the first conveyor belt 50 is conveyed through the respectivetreatment zones of the conveyor dishwasher 1 is higher than theconveying speed at which an item 100 of washware 101, 102, 103 which isheld by the second conveyor belt 51 is conveyed through the respectivetreatment zones of the conveyor dishwasher 1.

However, as an alternative to this, it goes without saying that it isalso possible to provide an associated drive apparatus for each conveyorbelt 50, 51 for the purpose of driving the corresponding conveyor belt50, 51 in such a way that an item of washware which is held by therespective conveyor belt 50, 51 is conveyed through the respectivetreatment zones of the conveyor dishwasher 1 at a conveying speed whichis or can be set individually for the respective conveyor belt 50, 51.

A further embodiment of the solution according to the invention will bedescribed below with reference to the illustrations in FIGS. 3 a and 3b. Specifically, these figures schematically show the machine outlet-endregion of a second exemplary embodiment of a conveyor apparatus 2 whichis suitable for use in a conveyor dishwasher 1 according to theillustration in FIG. 1.

The embodiment of the conveyor apparatus 2 which is illustrated in FIGS.3 a and 3 b differs from the embodiment which is described above withreference to the illustrations in FIGS. 2 a and 2 b in that, in additionto the first and second conveyor belts 50, 51, a further conveyor belt52 is provided. In the embodiment which is illustrated in FIGS. 3 a and3 b, this further conveyor belt 52 runs parallel to the first and secondconveyor belts 50, 51 and serves to hold cutlery or cutlery-likewashware 103. In this case, provision is preferably made for the furtherconveyor belt 52 to run directly next to the first conveyor belt 50 andbetween the first and second conveyor belts 50, 51.

Like the first conveyor belt 50, the further conveyor belt 52 also has areduced width in comparison to the total belt surface area, and inparticular in comparison to the width of the second conveyor belt 51, inorder to ensure minimal utilization of the surface area of the totalbelt surface area. In other words, despite the provision of the firstconveyor belt 50 and of the further conveyor belt 52, the secondconveyor belt 51 is suitable, as before, for holding, for example, racksof glasses or two items of washware which are arranged next to oneanother, for example a plate 101 and a bowl 102.

It is likewise preferred if, after passing through the conveyordishwasher 1, the cutlery 103 which is held by the further conveyor belt52 falls into a container which is provided at the machine outlet, thisenabling a further reduction in operating personnel at the machineoutlet. In particular, this embodiment enables handling actions forcutlery to be completely dispensed with both at the machine inlet (dirtyend of the conveyor dishwasher 1) and at the machine outlet (clean endof the conveyor dishwasher 1).

The concept of the plurality of conveyor belts which run in parallel canbe extended virtually as desired in this sense and various combinationsof conveyor belts which are specially provided for specific types ofwashware are possible. In addition to the above-described solutions inwhich up to three conveyor belts 50, 51, 52 which run in parallel areprovided, it is feasible, in particular, to provide special conveyorlanes for plates 101 and bowls 102 since automatic destacking systemsfor these types of washware are already known from semi- and fullyautomatic technology.

Therefore, with regard to a conveyor dishwasher 1 which operates asefficiently as possible, it is advantageous if, in addition to the firstconveyor belt 50 which is specially designed for holding trays ortray-like washware 100, and in addition to the further conveyor belt 52which is specially designed for holding cutlery 103, further conveyorbelts or conveyor belt lanes which are designed in respect of a specialtype of washware are provided.

In this connection, reference is made to the embodiment which isillustrated in FIGS. 4 a and 4 b. The conveyor apparatus 2 which ispartially illustrated in these figures corresponds substantially to theembodiment which is described above with reference to the illustrationin FIGS. 3 a and 3 b, but with the second conveyor belt 51 now havingbeen subdivided into a conveyor lane for the type of washware “plates”and a further conveyor lane for the type of washware “bowls”. In otherwords, in the embodiment which is illustrated in FIGS. 4 a and 4 b, thesecond conveyor belt 51 is subdivided into two conveyor belts 51 a, 51 bwhich run parallel to one another. Although not illustrated in thedrawings, each conveyor belt 51 a, 51 b has an automatic stacking ordestacking device at the machine inlet (dirty end of the conveyordishwasher 1) and/or at the machine outlet (clean end of the conveyordishwasher 1) in order to stack plates 101 into or to destack plates 101from the conveyor belt 51 a and in order to stack bowls 102 into theconveyor belt 51 b or to destack bowls 102 from the conveyor belt 51 b.

This subdivision of the second conveyor belt 51 into special lanes andautomated stacking and destacking increase the degree of automation ofthe conveyor dishwasher 1, and therefore working time can be saved bothat the clean end and at the dirty end of the conveyor dishwasher 1. Thedishwashing process therefore runs more efficiently and its total lengthis reduced, and therefore, in addition to working time, resources canalso be saved.

It is feasible for a common drive apparatus to be provided for thesecond conveyor belt 51 and the at least one further conveyor belt 52,or for the conveyor belt 51 which is subdivided into two conveyor belts51 a, 51 b and the at least one further conveyor belt 52, thecorresponding conveyor belts 51, 51 a, 51 b, 52 being jointly driven bymeans of the common drive apparatus. The conveying speed of eachconveyor belt 50, 51, 51 a, 51 b, 52 can preferably be set individually.

The illustration in FIG. 4 b shows that the respective upper faces ofthe conveyor belts 50, 51 a, 51 b and 52 of the conveyor apparatus 2 liein a common horizontal plane. This allows washware to also be heldacross a plurality of conveyor belts 50, 51 a, 51 b and 52, that is tosay by a plurality of conveyor belts 50, 51 a, 51 b and 52 at the sametime.

It should be noted that the invention is not restricted to the exemplaryembodiments which are illustrated above with reference to the drawings,but rather can be gathered by examining all the individual featuresdisclosed in these exemplary embodiments together.

1. A conveyor dishwasher (1), having at least one wash zone (10, 11.1,11.2, 12) and at least one final rinse zone (13) and also having aconveyor apparatus (2) for conveying washware (100, 101, 102, 103)through the at least one wash zone (10, 11.1, 11.2, 12) and the at leastone final rinse zone (13), characterized in that the conveyor apparatus(2) has a first conveyor belt (50) for trays or tray-like washware (100)and a second conveyor belt (51), which runs parallel to the firstconveyor belt (50), for other washware (101, 102, 103), and in that thefirst conveyor belt (50) has a width which is reduced in comparison tothe second conveyor belt (51) in such a way that a tray or a tray-likeitem (100) of washware can be held by the first conveyor belt (50) onlywhen it is in a state in which it is placed on edge and is orientedparallel to the conveying direction (T).
 2. Conveyor dishwasher (1)according to claim 1, with the tray or tray-like washware (100) which isto be held by the first conveyor belt (50) having a peripheral border ora peripheral edge, and with the first conveyor belt (50) being designedto hold the tray or tray-like item of washware (100) which is supportedon the first conveyor belt (50) by means of a border or edge region(100′).
 3. Conveyor dishwasher (1) according to claim 1 with a guidewhich is associated with the first conveyor belt (50) being provided forguiding a tray or tray-like item (100) of washware which is held by thefirst conveyor belt (50) as it is conveyed through the at least one washzone (10, 11.1, 11.2, 12) and the at least one final rinse zone (13). 4.Conveyor dishwasher (1) according to claim 3, with the guide having aguide groove (60), which is formed in the first conveyor belt (50) andruns in the longitudinal direction of the first conveyor belt (50), forholding a border or edge region (100′) of a tray or tray-like item (100)of washware which is placed on the first conveyor belt (50).
 5. Conveyordishwasher (1) according to claim 3 with the guide having at least oneupper guide element (61), which is situated opposite the first conveyorbelt (50), for holding a region (100″) of a tray or tray-like item (100)of washware which is placed in the first conveyor belt (50), with thisregion (100″) being situated opposite the border or edge region (100′)by means of which the tray or tray-like item (100) of washware issupported on the first conveyor belt (50).
 6. Conveyor dishwasher (1)according to claim 5, with the at least one upper guide element (61)being in the form of a guide rail.
 7. Conveyor dishwasher (1) accordingto claim 5 with the at least one upper guide element (61) beingadjustable in the vertical direction for the purpose of matching theguide to the height of a tray or tray-like item (100) of washware whichis to be held by the first conveyor belt (50) and is placed on edge. 8.Conveyor dishwasher (1) according to claim 3 with a machine outlet beingprovided downstream of the at least one final rinse zone (13) as seen inthe conveying direction (T), with the guide which is associated with thefirst conveyor belt (50) being designed to transfer a tray or tray-likeitem (100) of washware, which is held on the first conveyor belt (50),from its state in which it is placed on edge to its horizontallyoriented normal state and to destack said tray or tray-like item ofwashware at the machine outlet.
 9. Conveyor dishwasher (1) according toclaim 1 with a belt guide (62) which is associated with the firstconveyor belt (50) being provided for guiding the first conveyor belt(50), with the belt guide (62) being fixed to belt rod shafts (55) whichare part of the second conveyor belt (51).
 10. Conveyor dishwasher (1)according to claim 9, with the belt guide (62) being designed to supportand/or to guide a border or edge region (100′) of a tray or tray-likeitem (100) of washware which is placed on edge.
 11. Conveyor dishwasher(1) according to claim 1 with the first conveyor belt (50) beingembodied by means of drive belts, in particular by means of flat belts,V-belts, toothed belts or round belts.
 12. Conveyor dishwasher (1)according to claim 1 with at least one further conveyor belt (52) whichruns parallel to the first and second conveyor belts (50, 51) also beingprovided, in particular a further conveyor belt (52) for cutlery (103),this further conveyor belt running directly next to the first conveyorbelt (50) and between the first and second conveyor belts (50, 51). 13.Conveyor dishwasher (1) according to claim 12, with a common driveapparatus being provided for the second and the at least one furtherconveyor belt (51, 52), the second and the at least one further conveyorbelt (51, 52) being jointly driven by means of the said common driveapparatus.
 14. Conveyor dishwasher (1) according to claim 1 with acommon drive apparatus being provided for the first and second conveyorbelts (50, 51), the first and second conveyor belts (50, 51) beingjointly driven by means of the said common drive apparatus.
 15. Conveyordishwasher (1) according to claim 14, with the first conveyor belt (50)being connected to the common drive apparatus by means of a first driveshaft which is associated with the first conveyor belt (50) and a firstgear mechanism apparatus which is associated with the first conveyorbelt (50), with the second conveyor belt (51) being connected to thecommon drive apparatus by means of a second drive shaft which isassociated with the second conveyor belt (51) and a second gearmechanism apparatus which is associated with the second conveyor belt(51), and with the respective transmission ratio of the first and thesecond gear mechanism apparatus being different in such a way that theconveying speed at which an item (100) of washware which is held by thefirst conveyor belt (50) is conveyed through the at least one wash zone(10, 11.1, 11.2, 12) and the at least one final rinse zone (13) ishigher than the conveying speed at which an item of washware (101, 102,103) which is held by the second conveyor belt (51) is conveyed throughthe at least one wash zone (10, 11.1, 11.2, 12) and at least one finalrinse zone (13).
 16. Conveyor dishwasher (1) according to claim 13 withthe respective conveyor belts (50, 51, 52) being connected to the commondrive apparatus by means of a common drive shaft.
 17. Conveyordishwasher (1) according to claim 1 with an associated drive apparatusbeing provided for each conveyor belt (50, 51, 52) for the purpose ofdriving the corresponding conveyor belt (50, 51, 52) in such a way thatan item (100, 101, 102, 103) of washware which is held by the respectiveconveyor belt (50, 51, 52) is conveyed through the at least one washzone (10, 11.1, 11.2, 12) and the at least one final rinse zone (13) ata conveying speed which is or can be set individually for the respectiveconveyor belt (50, 51, 52).
 18. Conveyor dishwasher (1) according toclaim 17, with the conveying speed at which an item (100) of washwarewhich is held by the first conveyor belt (50) is conveyed through the atleast one wash zone (10, 11.1, 11.2, 12) and the at least one finalrinse zone (13) being higher than the conveying speed at which an item(101, 102, 103) of washware which is held by the second conveyor belt(51) is conveyed through the at least one wash zone (10, 11.1, 11.2, 12)and the at least one final rinse zone (13).
 19. Conveyor dishwasher (1)according to claim 1 with the respective upper faces of the conveyorbelts (50, 51, 52) of the conveyor apparatus (2) lying in a commonhorizontal plane in such a way that washware (100, 101, 102, 103) can beheld by a plurality of conveyor belts (50, 51, 52) at the same time. 20.Conveyor dishwasher (1) according to claim 1 with the second conveyorbelt (51) being subdivided into a plurality of conveyor belts (51 a, 51b) which run parallel to one another and can in each case be associatedwith a specific type of washware.